The "Bush tax cuts," passed in 2001 and 2003, remain the single largest
cause of America's structural deficit -- that is, the deficit not caused
by the collapse in tax revenue when the economy goes into recession.

Those cuts are set to expire this year. 

I understand the fear that this is not a good time to raise taxes. But
the impact of marginal shifts in tax rates on growth is pretty unclear.

The Washington Post, August 2, 2010